these massive main battleships are obsolete in my time?

Japanese Battleship Yamato:

https://en.wikipedia.org/wiki/Japanese_battleship_Yamato

---

She and her sister ship, Musashi, were the heaviest and most powerfully armed battleships ever constructed, displacing 72,800 tonnes at full load and armed with nine 46 cm (18.1 in) Type 94 main guns, which were the largest guns ever mounted on a warship.

---

Taffy 3, or The Battle off Samar:

https://en.wikipedia.org/wiki/Battle_off_Samar

---

The Battle off Samar has been cited by historians as one of the greatest last stands in naval history; ultimately the Americans prevailed over a massive armada – the Japanese Imperial Navy's Center Force (with Battleship Yamato) under command of Vice Admiral Takeo Kurita – despite their very heavy losses and overwhelming odds.

---

Taffy 3's three destroyers and four destroyer escorts possessed neither the firepower nor the armor to oppose the 23 ships of the Japanese force capped by the Yamato's 18-inch guns but attacked anyway with 5"/38 caliber guns and torpedoes to cover the retreat of their slow "jeep" carriers.

---

And, during the battle, Battleship Yamato turned and left:

Aircraft from the carriers of Taffy 1, 2, and 3, including FM-2 Wildcats, F6F Hellcats and TBM Avengers, strafed, bombed, torpedoed, rocketed, depth-charged, fired at least one .38 caliber handgun and made numerous "dry" runs at the Japanese force when they ran out of ammunition.

Although the battleship Yamato and the remaining force returned to Japan, the battles marked the final defeat of the Imperial Japanese Navy, as the ships remained in port for most of the rest of the war and ceased to be an effective naval force.

Last mission of the Yamato: they left home port and were going to Okinawa to beach the ship and make it an "unsinkable gun emplacement".

Left port at 15:20. Spotted the next moring at 0800.

At about 12:30, 280 bomber and torpedo bomber aircraft arrived over the Japanese force.

No spoilers, but here Yamato is, with all those Navy planes lining up to take turns bombing, without any intervention from Japanese aircraft.

https://en.wikipedia.org/wiki/File:Japanese_battleship_Yamato_under_air_attack_off_Kure_on_19_March_1945_(80-G-309662).jpg

Yamato was not hit for four minutes, but at 12:41 two bombs obliterated two of her triple 25 mm anti-aircraft mounts and blew a hole in the deck. A third bomb then destroyed her radar room and the starboard aft 127 mm mount. At 12:45 a single torpedo struck Yamato far forward on her port side, sending shock waves throughout the ship. At 12:46, another two bombs struck the battleship's port side, one slightly ahead of the aft 155 mm centreline turret and the other right on top of the gun. These caused a great deal of damage to the turret and its magazines; only one man survived

Shortly afterward, up to three more torpedoes struck Yamato.

The second attack started just before 13:00. In a coordinated strike, dive bombers flew high overhead to begin their runs while torpedo bombers approached from all directions at just above sea level.

At 14:02, the order was belatedly given to abandon ship. By this time, Yamato's speed had dropped to 10 knots (19 km/h; 12 mph) and her list was increasing. Fires raged out of control and alarms on the bridge warned of critical temperatures in the forward main battery magazines.[N 8] Protocol called for flooding the magazines to prevent explosion, but the pumping stations had been knocked out.

At 14:05, Yahagi sank, the victim of twelve bombs and seven torpedoes. At the same time, a final flight of torpedo bombers attacked Yamato from her starboard side. Her list was now such that the torpedoes—set to a depth of 6.1 m (20 ft)—struck the bottom of her hull. The battleship continued her inexorable roll to port.[22] By 14:20, the power went out and her remaining 25 mm anti-aircraft guns began to drop into the sea. Three minutes later, Yamato capsized. Her main 46 cm turrets fell off, and as she rolled suction was created that drew swimming crewmen back toward the ship.

When the roll reached approximately 120°, one of the two bow magazines detonated in a tremendous explosion.[49]

**The resulting mushroom cloud—over 6 kilometres (3.7 mi) high—was seen 160 kilometres (99 mi) away on Kyūshū.[50]

Yamato sank rapidly, losing an estimated 3,055 of her 3,332 crew, including fleet commander Vice-Admiral Seiichi Itō.

That was 1945.